There are many theories about childhood trauma and how it affects the bodies and minds of children and how these experiences shape adults. One of the most interesting of all of them is what is called the polyvagal theory.

First described in 1994 by Stephen W. Porges, a distinguished university scientist, the polyvagal theory has caught the attention of millions including therapists and theorists of all types.

This is the first of a series on the polyvagal theory and this piece will focus on what polyvagal theory is and why should you learn about it? For the sake of this piece, we shall examine the polyvagal theory in light of childhood trauma.

Why You Should Learn More About Polyvagal Theory

There are many reasons one should become enlightened to the polyvagal theory, least of which is to understand why those bothersome behaviors such as hypervigilance are there and how to deal with them.

Another reason to learn more is that it is horrible to be a mystery to oneself reacting to danger that is not there as though one is back in situations that happened decades in the past.

The polyvagal theory also explains why people who were victimized as children freeze when confronted with a sexual predator such as a rapist or other abuser today. It isn’t because they don’t want to scream or run, their brain has shut down and they cannot.

What is the Polyvagal Theory?

 The Vagal Nerve is the longest cranial nerve controlling a human’s inner nerve center, the parasympathetic nervous system. It oversees a vast range of vital functions communicating sensory input from outside triggers to the rest of the body.

Polyvagal theory emphasizes the evolutionary development of two systems: the parasympathetic nervous system which is ultimately connected to the vagal nerve and the sympathetic nervous system. Each has its own function, and cause the body to react differently before, during, and after a traumatic or stressful event. If these two systems become damaged from excessive and recurrent trauma, a break down occurs and mental illnesses such as CPTSD and anxiety disorders may result.

The sympathetic nervous system gets the body ready for the fight/flight/freeze response. With the fight or flight response, the sympathetic nervous system begins revving up the heartbeat and blood pressure and stealing blood from the body to make muscles ready to run. If there is nowhere to run and no hope of escape, the sympathetic nervous system will cause the person to freeze or collapse (both forms of dissociation).

The parasympathetic nervous system is a calming force, that when kicked in, allows the heart rate and blood pressure to lower, calming down the body after a traumatic event.

If the sympathetic nervous system is hyper-aroused then the body suffers from a lack of adequate blood supply as the person is always ready to flee or fight. This damages the person’s ability to calm down after being triggered by something that even barely resembles the danger that damaged their sympathetic system.

If the parasympathetic system does not kick-in appropriately, the body suffers because blood pressure can suddenly drop leading to fainting and other physical problems.

The Causes of Nervous System Damage

The leading cause of damage to the nervous system is the overwhelming and chronic washing of the brain by stress hormones brought on by severe and repeated childhood trauma.

Stress hormones are notoriously known to damage a child’s brain including the vagal nerve and both the parasympathetic and sympathetic nervous systems.

Adverse childhood experiences (ACEs) are some of the events that can cause such damage and they include any or all of the following:

  • Physical abuse
  • Sexual abuse
  • Emotional abuse
  • Physical neglect
  • Emotional neglect
  • Exposure to domestic violence
  • Household substance abuse
  • Household mental illness
  • Parental separation or divorce
  • Incarcerated household member

Clearly, ACEs encompasses intergenerational trauma, personal trauma, complex trauma and may result in complex post-traumatic stress disorder. The more ACEs a child experiences, the more likely they are to have damage to their parasympathetic and sympathetic nervous systems.

The Differences in the Symptoms of Sympathetic vs. Parasympathetic Damage

As one can imagine, there are many side-effects of having damage to either the sympathetic or parasympathetic systems. So, let’s break that down. How does each feel, and what are the responses?

Sympathetic Nervous System Damage. There are many natural effects that the sympathetic nervous system has on the body when triggered including the following:

  • Sensing a threat and freezing to scan for the danger
  • Releasing cortisol, norepinephrine, epinephrine, and other stress hormones to prepare for the body for fight or flight
  • Feeling angry, afraid, or very anxious
  • Digestion and other bodily functions considered non-essential slow to allow blood to rush to the muscles
  • The need to run away hit something, or react physically in some way become overwhelming
  • Senses become focused and hyperalert

When these reactions become chronic due to childhood trauma, sensing a threat becomes sensing a perceived threat because of the past event. The person will release stress hormones in response to this perceived threat just as if it were a real one and become angry, afraid, or filled with anxiety. The immune and digestive systems shut down to make more blood for the muscles so that we can run away, and we might react by wanting to hit something (or someone). Our senses remain in a state of constant hyper-alertness ready for the next trigger to happen.

Parasympathetic Nervous System Damage. The job of the parasympathetic system is two-fold: to calm us down after a fright, and to keep us in a frozen state to help us survive so we can fight or flight again. When the parasympathetic nervous system is damaged by childhood trauma, either or both of the functions mentioned above breaks down leaving the person with the following problems:

  • Feelings of numbness, dissociation, hopelessness, shame, trapped or disconnected
  • Spacing out
  • Greatly decreased heart rate, blood pressure, sexual arousal, and lowered immune system response
  • Have difficulty finding words
  • Loss of awareness
  • Inability to consolidate memories properly
  • Lowered ability to feel pain

Many survivors who have damaged parasympathetic nervous systems dissociate (experience of feeling disconnected from the sense of self) and have problems spacing out. They may be ill more than other people because their immune system is compromised. They have trouble finding the appropriate words to express how they are feeling and experience a lack of self-awareness. Survivors often have memory problems and experience a lowered ability to experience pain which is dangerous because pain is necessary to know when one is injured.

The Good News

According to the polyvagal theory, all is not gloom and doom as the damages done to the parasympathetic and sympathetic nervous systems can be healed with much time, learning, therapy, and elbow grease.

Therefore, it is well worth the while of anyone experiencing any of the symptoms listed in the above paragraphs to ask their doctor or therapist for treatment based on the theory of Stephen Porges.

“Healing takes courage, and we all have courage, even if we have to dig a little to find it.” – Tori Amos

“Healing may not be so much about getting better, as about letting go of everything that isn’t you – all of the expectations, all of the beliefs – and becoming who you are.” – Rachel Naomi Remen

If you or a loved one are living in the despair and isolation that comes with complex post-traumatic stress disorder, please, come to us for help. The CPTSD Foundation offers a wide range of services including:

All our services are reasonably priced or free and will help you gain more insight into how complex post-traumatic stress disorder is altering your life and how you can overcome it, sign-up, we’ll be glad to help you.